From: tcmay@got.net (Timothy C. May)
Date: Fri, 10 Nov 1995 02:24:19 +0800
To: cypherpunks@toad.com
Subject: Re: Timed-release crypto and information economics
Message-ID: <acc774f813021004a77a@[205.199.118.202]>
MIME-Version: 1.0
Content-Type: text/plain


At 3:58 PM 11/9/95, Beavis B. Thoopit wrote:

>Does there exist a storage device that, due to _dynamics_ (or other
>factor), prevents the total contents being read in one instance?
>
>Bubble memory device?  Torsion wire memory device?

"All crypto is economics."

There's a literature of sorts on "tamper-resistant modules," or
"tamper-responding modules." Chips or packages that either resist tampering
(= reading, opening, etc.) or that give indication they have been read,
opened, or otherwise accessed.

"Quantum cryptography" aims at providing a "read only once" system. Consult
the vast number of articles and comments available.

Basically, any secret stored in (traditional) hardware can be gotten with
enough money. The issue is the amount of money it takes, and how many
tries, to open the hardware.

(And it may take a lot. Or destroy a lot of chips in the process. The
similarities to bomb disposal are obvious: it may be _possible_ to disarm a
bomb, but a lot of "learning" is likely to take place first.)

Search the archives if you wish for previous articles I and others have
written on reverse-engineering chips with electron beam probes, for
example.

--Tim May

Views here are not the views of my Internet Service Provider or Government.
---------:---------:---------:---------:---------:---------:---------:----
Timothy C. May              | Crypto Anarchy: encryption, digital money,
tcmay@got.net  408-728-0152 | anonymous networks, digital pseudonyms, zero
Corralitos, CA              | knowledge, reputations, information markets,
Higher Power: 2^756839      | black markets, collapse of governments.
"National borders are just speed bumps on the information superhighway."